Does doubling the frequency of a wave source double the speed of the waves?

AI Thread Summary
Doubling the frequency of a wave source does not double the speed of the waves; wave speed is determined by the properties of the medium. When frequency increases, the wavelength decreases proportionally, keeping the wave speed constant in a given medium. The equation mentioned, v = 2πf, refers to the speed of a particle on a wave rather than the wave speed itself. Changes in wave speed occur only when waves transition between different media. Understanding the relationship between frequency, wavelength, and wave speed is essential for accurate physics concepts.
DarylMBCP
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Homework Statement


Does doubling the frequency of a wave source double the speed of the waves as according to the wave equation because one of my sources says that this is false.


Homework Equations


Speed = Wavelength • Frequency
 
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Speed of the waves depends on the properties of the medium, not on the frequency of the source. If frequency of the source changes , the wavelength in the medium changes.
 


However, aren't the frequency and wavelength of the wave proportional to the speed of the wave meaning that doubling the frequency of a wave source doubles the speed of the waves?
 


When you double the frequency, you halve the wavelength. The speed of the wave stays the same for a given medium.
Waves change speed when they enter a different medium. Light going from air into water changes in speed which we observe as a change in direction. A pencil in a glass of water looks broken.
 


Isn't v = 2pi * f though too? So doubling f would double v, right?

Actually I think that is the speed of a particle on a wave
 


cashmoney805 said:
Isn't v = 2pi * f though too? So doubling f would double v, right?

Actually I think that is the speed of a particle on a wave
That's not a speed; it has the wrong units. The relation that you have written looks like a common relation between two types of frequencies, but one of the variables that you have used is nonstandard.
 


Oh woops, I mean 2pi*f*Amplitude
 


cashmoney805 said:
Oh woops, I mean 2pi*f*Amplitude
Then that is the "speed" of the displacement associated with the oscillation. (Note that "speed" can be a generalized concept; not just length per time.)
 


Thanks for responding but when and what is that equation used for? Oh ya, what is 2pi in this case?
 
  • #10


Carid said:
When you double the frequency, you halve the wavelength. The speed of the wave stays the same for a given medium. Waves change speed when they enter a different medium.

However, how if you double the frequency and retain the wavelength of that wave? Won't this cause that wave to change its speed too? Is this possible in the first place?
 
  • #11


Daryl,
You are treating frequency and wavelength as if they are unconnected.

rl.bhat told us clearly "Speed of the waves depends on the properties of the medium, not on the frequency of the source. If frequency of the source changes , the wavelength in the medium changes. "
 
  • #12


DarylMBCP said:
Thanks for responding but when and what is that equation used for? Oh ya, what is 2pi in this case?
That equation is for speed of a particle on a string, going up and down. I didn't mean to write an equation that wasn't relevant to the question. I thought that equation gave you the wave speed, but after I posted I realized I was wrong. Instead of deleting my post, I just corrected it in case anyone read it and got confused. Sorry!
 
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